Semaglutide Reconstitution Calculator
Reconstituting compounded semaglutide? Enter the vial, the water and your dose to see exactly where to stop on the insulin syringe — and redo the math at every titration step.
Water doesn't change the dose — it changes how many units the dose takes up.
U-100 and U-50 share the same scale — 100 units per mL. The U-50 just has half the barrel (0.5 mL), so it stops at 50. The U-40 marks 40 units per mL, which is a different scale. Check what's printed on yours.
Fill in the vial, the water and the dose to see the result.
Personal journal. Not medical advice.
How the semaglutide calculation works
Vial, water and dose go in; the syringe mark comes out. Each step below is solved with a 5 mg vial in 2 mL — the most common dilution for compounded semaglutide.
Concentration
Milligrams in the vial ÷ mL of water = how many mg sit in each mL.
vial ÷ water = concentration5 mg ÷ 2 mL = 2.5 mg/mLVolume per dose
Dose ÷ concentration = how many mL you need to draw.
dose ÷ concentration = mL0.25 mg ÷ 2.5 = 0.1 mLUnits on the syringe
mL × 100 on a U-100 or U-50 syringe (or × 40 on a U-40) = the mark to stop at.
mL × 100 = units0.1 mL × 100 = 10 unitsThe whole thing in one formula
units = dose ÷ (vial ÷ water) × 100Vial in mg, water in mL, dose in mg. The 100 covers U-100 and U-50; swap it for 40 if your syringe is a U-40.
A 5 mg vial with 2 mL of water gives 2.5 mg/mL. A 0.25 mg dose takes up 0.1 mL — that's 10 units on a U-100 syringe.
The conversions people look up
How many units is 0.25 mg of semaglutide?
10 units on a U-100 syringe, with a 5 mg vial reconstituted in 2 mL.
And 0.5 mg?
20 units in the same vial. Units scale in step with the dose.
And 1 mg and 2.4 mg?
40 and 96 units. The top dose takes up nearly the whole syringe at that dilution.
What's the concentration of a 5 mg vial in 2 mL?
2.5 mg/mL. With 1 mL of water it would be 5 mg/mL, and every mark would halve.
Units by dose and dilution
A 5 mg vial on a U-100 syringe. Columns are the water you used to reconstitute.
| Dose | 1 mL | 1.5 mL | 2 mL | 3 mL |
|---|---|---|---|---|
| 0.25 mg | 5 | 7.5 | 10 | 15 |
| 0.5 mg | 10 | 15 | 20 | 30 |
| 1 mg | 20 | 30 | 40 | 60 |
| 1.7 mg | 34 | 51 | 68 | 102 |
| 2.4 mg | 48 | 72 | 96 | 144 |
Semaglutide in practice
Semaglutide is a once-weekly GLP-1 receptor agonist. In manufactured pens the dose is already set by the dial and there's nothing to work out. The math only shows up with compounded semaglutide, which arrives lyophilized in a vial — there, the dilution is chosen by whoever reconstitutes it, and the number of units moves with it.
The dose path is usually gradual, stepping up every four weeks: 0.25 mg, then 0.5, then 1 mg, and on to 1.7 and 2.4 mg depending on response and clinical guidance. The first step exists so the body can adjust, not to treat — which is why nobody starts at the top.
Every step is a new mark on the syringe. Because units scale with the dose, a vial that read 10 units at 0.25 mg will read 20 at 0.5 mg and 40 at 1 mg. Redoing the math on switch week is the habit that prevents the most common titration mistake.
Do this math once. Once.
In PepPro you enter the vial and the water a single time. From then on the app works out every injection on its own, shows the units on a visual syringe, reminds you at the right moment and keeps the whole history.
- Your reconstitution stays saved per vial
- Exact units on a visual syringe before you inject
- Reminders, titration and injection-site rotation
- Full history of doses, weight and how you feel
Exact units on a visual syringe before you inject
Good question. We've got answers.
Didn't find what you were after? Email us at contato@upsidecompany.com.br.
Let the vial come to room temperature, wipe the rubber stopper with alcohol, draw the bacteriostatic water into the syringe and let it run slowly down the inner wall of the vial. Swirl gently until dissolved — never shake, since agitation can degrade the peptide. Store refrigerated and away from light.
The solution has to end up clear, with nothing floating in it. If the powder doesn't dissolve within a few minutes of gentle swirling, or the liquid turns cloudy or shows flakes, don't use it — and never shake to speed things up, since agitation degrades the peptide.
Anywhere from 1 mL to 3 mL works; the difference is how easy the syringe is to read. With 2 mL, a 5 mg vial gives 20 doses of 0.25 mg at 10 units each — a round number that's easy to double-check. If you're already on higher doses, less water keeps the injection volume smaller.
You don't need it. Those pens come pre-mixed with the dose set by the dial: there's no reconstitution and no conversion to units. This calculator is for compounded semaglutide, which comes as a lyophilized vial you have to dilute yourself.
Yes, proportionally. If 0.25 mg reads 10 units in that vial, 0.5 mg reads 20 and 1 mg reads 40. The concentration only changes when you open a new vial with a different amount of water — but the mark on the syringe changes at every titration step.
Yes — that's exactly what PepPro is for. Enter the vial and the reconstitution once and the app takes over: it works out every injection, shows the units on a visual syringe, reminds you when it's time and keeps the history of doses, weight and how you feel.
No. PepPro is a personal journal and this calculator is an educational tool. Nothing here replaces a qualified healthcare professional — they're the one who decides whether, how much and how you should use any compound.
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Personal journal. Not medical advice.
Disclaimer
This calculator is for informational and educational purposes only and is not medical advice. Always confirm dosing with a qualified healthcare professional and double-check your own measurements before administering anything.